sh: flag kdump as broken on SMP for now.

There's still quite a bit of shootdown logic that needs to be hacked up
to support SMP for kdump properly, so just add in a BROKEN_ON_SMP
dependency for now.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -633,7 +633,7 @@ config KEXEC
 
 config CRASH_DUMP
 	bool "kernel crash dumps (EXPERIMENTAL)"
-	depends on SUPERH32 && EXPERIMENTAL
+	depends on SUPERH32 && EXPERIMENTAL && BROKEN_ON_SMP
 	help
 	  Generate crash dump after being started by kexec.
 	  This should be normally only set in special crash dump kernels